1. Field of the Invention
This invention relates to a method and an apparatus for recording an information on an optical recording medium having land and groove tracks.
2. Description of the Related Art
Nowadays, a need of larger capacity has been increased in an optical recording/reproducing field or an opto-magnetic recording/reproducing field in order to record an information that is greatly enlarged in the quantity. Accordingly, in optical discs such as a DVD-RAM (digital versatile disc-random access memory) and so on, there has been suggested so-called a land/groove recording system having an information recorded on both of land and groove tracks. Actually, a disc of a phase-change recording system such as DVD-RAM and a disc of an opto-magnetic recording system such as ASMO (Advanced Storage Magneto-Optical) are known as the disc of land/groove recording system.
Referring to FIGS. 1 and 2, there are shown an optical recording medium 20 having land tracks 22 and groove tracks 24. The optical recording medium 20 consists of an information recording and reproducing layer 26, a reflective layer 28 and a protective layer 32 formed sequentially under a substrate 30. The information recording and reproducing layer 26 records an information and the reflective layer 28 reflects a light beam. The substrate 30 and the protective layer 32 are formed by a material hating relatively low heat conductivity. For example, PMMA (Poly Methyl MethAcrylate) can be used as the substrate material and the protective layer 32 can be formed by a resin class. Meanwhile, the information recording and reproducing layer 26 and the reflective layer 28 are formed by the material having a relatively high heat conductivity. The information recording and reproducing layer 26 can consist of a recording layer 26a, a reproduction supporting layer 26b and a reproducing layer 26c, as shown in FIG. 3. The recording layer 26a and the reproduction supporting layer 26b are formed by a TbFeCo and a GdFe, respectively. The reproducing layer 26c and the reflective layer 28 are made of a GdFeCo and a Al, respectively.
In such an optical recording medium as described above, the information recording and reproducing layer 26 positioned at the land track 22 lies adjacent to the materials having the high heat conductivity. Meanwhile, the information recording and reproducing layer 26 positioned at the groove track 24 is contiguous to the materials having a low heat conductivity. Accordingly, the land and groove tracks 22 and 24 have a different thermal conductivity when a light beam is irradiated on the optical recording medium 20. As a result, a thermal characteristic difference appears between the land and groove tracks 22 and 24.
The thermal characteristic difference allows recording pits formed on the land and groove tracks 22 and 24 to have a different length although the light beam of the same recording power is irradiated on the optical recording medium with the land and groove tracks 22 and 24. In detail, the material on the areas adjacent to the land track 22 radiates a great amount of thermal energies when the light beam is irradiated on the land track 22. This results from that the material on the area adjacent to the land track 22 has the high heat conductivity. Thus, a relatively short recording pits are formed on the information recording and reproducing layer 26 corresponding to the land track 22. Meanwhile, the material on the areas adjacent to the groove track 24 radiates a small amount of thermal energies when the light beam is irradiated on the groove track 24. This results from that the material on the area adjacent to the groove track 24 has the low heat conductivity. Therefore, a relatively long recording pits are formed on the information recording and reproducing layer 26 corresponding to the land track 24. In other words, although the light beam having the same recording power is irradiated on the land and groove tracks 22 and 24, the recording pits formed on the land and groove tracks 22 and 24 have a different length according to the widths of the land and groove tracks 22 and 24 and the depth from the land track 22 to the groove track 24. Due to this, recording errors can be generated when the information is recorded on the optical recording medium.
Further, the recording errors can increase more and more as the capacity of the opical recording mdeium is enlarged. This results from the tact that the difference between the recording pits on the land and groove tracks 22 and 24 is enlarged in accordance with decreasing of the land and groove tracks 22 and 24 in width.
Accordingly, it is an object of the present invention to provide an optical information recording method and an apparatus that can form recording marks having the same length on a land and a groove track of an optical recording medium.
In order to achieve these and other objects of the invention, an optical information recording method according to an aspect of the present invention includes the steps of: identifying whether any one of a land and a groove track on an optical recording medium is accessed; and establishing differently an outputting manner of recording lights to be irradiated on the optical recording medium on the basis of a identifying resultant for the land and groove tracks.
An optical information recording method according to another aspect of the present invention allows a rotating speed of optical recording medium to be different depending on a land/groove identification signal for indicating a land and a groove track on the optical recording medium.
An optical information recording apparatus according to still another aspect of the present invention includes: distinguishing means for identifying whether any one of a land and a groove track is accessed; and recording means for establishing differently an outputting manner of recording lights to be irradiated on the optical recording medium on the basis of an identifying resultant of the distinguishing means and for performing a recording operation.